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McKenney" , Metin Kaya , Xuewen Yan , Thomas Gleixner , "Daniel Lezcano" , Suleiman Souhlal , kuyo chang , hupu , References: <33e60181-1809-44e1-bc4c-8ac7f79d49d6@amd.com> <20260327160017.GK3738010@noisy.programming.kicks-ass.net> <1515d405-62fc-4952-842f-b69e2bf192c0@amd.com> <20260402155055.GV3738010@noisy.programming.kicks-ass.net> <20260403095225.GY3738010@noisy.programming.kicks-ass.net> <1d2d4596-93d6-4d87-babc-084b8d6c2d98@amd.com> <20260403112810.GG3738786@noisy.programming.kicks-ass.net> <5e2337e7-24d8-4cc7-a86d-b8f5a19fb3ce@amd.com> <20260403143819.GC2872@noisy.programming.kicks-ass.net> <0f5b0dd9-ef6e-462b-ac89-6f37c4261241@amd.com> Content-Language: en-US From: K Prateek Nayak In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Received-SPF: None (SATLEXMB04.amd.com: kprateek.nayak@amd.com does not designate permitted sender hosts) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH2PEPF00000140:EE_|CY3PR12MB9606:EE_ X-MS-Office365-Filtering-Correlation-Id: bbd62515-0e23-4f65-5eff-08de9385f2d5 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|36860700016|82310400026|1800799024|376014|22082099003|18002099003|56012099003; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:satlexmb08.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(7416014)(36860700016)(82310400026)(1800799024)(376014)(22082099003)(18002099003)(56012099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: xUSZ/RONPDYdiac8onSJNORRqFKYO+D6N8EitP1oFVts5Dob7XkPOUisOh2qYm4D/ZBh+qEZ9ggTkOl/UuMotR7klHfIEFbqsI9GF9k1QhUvS1HzX0BzJ53nrRl9Ml6a7mc5Nka/2HgECX+7zLJEzJe+syIJPFmX+iXFtlEI3aWjhKfDnBtFKA7SHVC38LnMUL9cvXXlSVze21VejxUZBkYNtVOHak3UA3lEv1/j31PuZevxs1OYM98ahXLyVqI73nBx0AGgv45sIj8pALsu278D2NlYXhA4M0KGoLUP6g3FJevKr619ZEij/2KhIpuUZm9mUz4SjHEw2JNH9Pf/uHfhMUh1Vx7HPYrhlIZQN7fcsRKAFV1EhkRAOTJRFHYam/4jZfZx9kitupGwDbFagagB8Ls2zp+qpqTrJ7ifnNtd5GFpMlKCRSK+jN7Qw7Ez X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Apr 2026 02:41:04.6540 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: bbd62515-0e23-4f65-5eff-08de9385f2d5 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[satlexmb08.amd.com] X-MS-Exchange-CrossTenant-AuthSource: CH2PEPF00000140.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY3PR12MB9606 Hello John, On 4/4/2026 11:37 AM, John Stultz wrote: >> Also looking at proxy-exec-v27-WIP, I think that: >> >> set_task_blocked_on_waking(p, NULL) >> >> in try_to_wake_up() can be moved after ttwu_state_match() since >> otherwise, we skip waking the task but ttwu() will end up marking >> it PROXY_WAKING for a spurious wakeup. >> >> I don't think there is any harm in keeping it that way but during the >> next pick, __schedule() will end up seeing PROXY_WAKING and will block >> the task. >> >> Until it receives a genuine wakeup, it cannot participate in proxy which >> is a missed opportunity. > > So, actually, that caught my eye as well, and I think it can be > dropped completely. I just didn't have the time to experiment and > respin the series when I noticed it. > > My thinking: > 1) Since including your recent suggestions, proxy_needs_return() > handles both cases where its blocked_on a mutex or PROXY_WAKING. > 2) If its not on the runqueue, we'll clear blocked_on anyway after > setting TASK_WAKING > > So it seems like its harmless, but also unnecessary. I'll make sure > next week and will drop it in the next revision. Ack! I just thought you wanted to keep a clean: blocked_on: NULL -> MUTEX -> PROXY_WAKING -> NULL transition in all cases ;-) -- Thanks and Regards, Prateek